php - mysql: storing string larger than field size

Question

An attempt to store a string larger than the field (column) size will result in

• the query failing

or

• the string will be silently truncated to the max allowed length?

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In other words:

should I take care of truncate strings too long before storing them or can I just store them and let the underlying system truncate them for me ?

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Side note

I'm talking about data that I don't care if it gets truncated, of course.

Answer 1

It depends on the current SQL_MODE .

When mode is not strict, your query will produce only a warning, which is normally not visible to you unless requested explicitly. So in effect the string will be silently truncated to the max allowed length.

While in a strict mode, this query will result in a full-featured error and your query will fail

Answer 2

如果没有PHP级别的验证，则字符串将被截断